As I described wanting to do here, I actually did follow through and I printed out the photos and sent them off into the unknown.
I got one response out of the four mailings I sent. One.
It was from the 88-year-old woman who now lives (presumably alone) in my grandparent's old house in upstate Massachusetts, and it was delightful. I didn't get any photos (she promised to email some in March when her son comes down), but I did get some insight into what had been done to the house since 1972.